The invention concerns a joint for unfolding systems such as satellite solar generators. Preferred embodiments include joints with two joint halves, a hinge pin and a drive.
Unfolding systems such as large-area satellite solar generators consist, for example, of individual flexible segments that unfold after being transported into space.
The unfolding can be brought about by spring or motor-actuated unfolding joints that can be directly connected to the individual segments or connected to rigid extension arms that act on the segments.
To unfold large-area segments by means of springs, unfolding joints must be used that have large springs to provide sufficient unfolding torque. Such unfolding joints weigh a great deal, are large, and are therefore not very useful or useless in extreme cases for satellite solar generators.
A problem of the invention is to create a joint for unfolding systems that has sufficient unfolding torque, does not weigh much, and has small dimensions.
The problem is solved according to the invention by providing a joint for an unfolding system, which joint includes first and second joint parts, a hinge pin pivotally connecting the first and second joint parts, a large pulley rotatably mounted at the hinge pin and fixed to the first joint part, a small pulley disposed on the second joint part at a spacing from the large pulley, a cord partially wound on both the large and small pulleys, and a drive. The drive, when in use, operates to rotate the small pulley to wind the cord thereon. The cord is operable to rotate the large pulley and unfold the first and second joint parts with respect to one another into an unfolded state with said joint parts held in the unfolded state by a stop.
The invention has the advantage that small and light springs or motors can be used to generate a large amount of torque to better exploit the available installation area of such unfolding systems.
An exemplary embodiment of the invention will be further described in the following with reference to the drawing. An example of an unfolding joint for satellite solar generators with a spring drive will be described.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.